WOULD RATHER / WOULD SOONER + clause with the past subjunctive

Would rather/sooner + clause with the past subjunctive expresses that we would like someone else to do something.

I'd rather you didn't smoke in here. (I'd prefer you not to smoke in here.)
Tim would sooner I returned his camera. (Tim would like me to return his camera.)
Where would you rather I slept? (Where would you prefer me to sleep?)

This pattern can be rephrased by using a second conditional with prefer:

I would prefer it if you didn't smoke in here.